Toxic injury as the result of exposure to low molecular weight halogenated compounds is often the result of the formation of pharmacologically and/or toxicologically active products of biotransformation. An understanding of the mechanisms of toxic chemical action requires the elucidation of metabolic pathways of the compounds in question. Vinyl bromide has been known for some time to be decomposed in vivo with the liberation of inorganic bromide and other unknown products. We have demonstrated that exposure of rats to hepatotoxic concentrations of vinyl bromide by inhalation results in the liberation of pharmacologically significant quantities of inorganic bromide. Serum inorganic bromide levels rose to levels high enough to cause a qauntifiable central nervous system depression. The effects of bromide on the kidney in this context, the principal organ of excretion of bromide, remains unknown. Likewise the identify and fate of other products of biotransformation remain unknown. BIBLIOGRAPHIC REFERENCES: Van Stee, E.W., Patel, J.M., Gupta, B.N., Drew, R.T.: Consequences of Vinyl Bromide Debromination in the Rat. Sixteenth Annual Meeting, Society of Toxicology, Toronto, Canada, March 27-30, 1977. (Abstract) Van Stee, E.W., McConnell, E.E., Patel, J.M., and Hamlin, R.L.: The Inhalation Toxicology of the Refrigerant, chlorodifluoromethane (F-22). International Congress on Toxicology, Toronto, Canada, March 30-April 2, 1977. (Abstract)